A Novel Method for Fractured-Vuggy Reservoir Characterization Based on Stratigraphic Background Removal and Energy Tracing

Summary The recognition of fractured-vuggy core is a pivotal task in the characterization of fractured-vuggy reservoirs, where pores, fractures, cavities, fluids, and faults often overlap intricately. Sole reliance on seismic facies cannot provide an accurate and effective interpretation. Traditional methods such as coherence and curvature are no longer sufficient to meet the precision requirements of modern exploration and development. In this paper, we propose a novel methodology for characterizing fractured-vuggy systems in the complex reservoirs of the Y area in the Tarim Basin. Initially, through seismic interpretation, the top and bottom layers of the reservoir were determined. The target layer was extracted from the field seismic data to form an equal-depth body. Spatial wavenumber domain filtering was then applied to remove the stratigraphic background from the equal-depth body. Subsequently, the first eigenvalue of the gradient structure tensor (GST) of the fractured-vuggy body was extracted. Threshold and amplitude control were used to trace the energy ridge and identify the core of the fractured-vuggy body. Finally, the identification results were integrated and embedded into the field seismic data, yielding the final fractured-vuggy characterization volume. The actual application of the Y5 well area shows that the identified results are in good agreement with well logs, and it is an effective method to describe fractured-vuggy body. In addition, the application and analysis in the Y2 well area predict three favorable target points. In general, the proposed method for fractured-vuggy body characterization proves to be effective in complex fractured-vuggy development areas and can be promoted and applied as a new approach.